In November 2025, the Food and Agriculture Organization (FAO) and World Health Organization (WHO) convened a landmark expert consultation in Rome, Italy, that has produced recommendations poised to transform food safety standards for millions of people living with coeliac disease worldwide.
The Ad hoc Joint FAO/WHO Expert Consultation on Risk Assessment of Food Allergens established a critical reference dose (RfD) of 4 mg of gluten for precautionary allergen labelling, marking a significant advancement in protecting consumers with gluten-related disorders.
Coeliac disease and the gluten challenge
Coeliac disease is a chronic, immune-mediated intestinal and systemic disease affecting genetically predisposed individuals who are exposed to dietary gluten proteins from wheat (including spelt and khorasan wheat), rye, barley, oats or their hybridised strains, and products thereof. Unlike IgE-mediated food allergies that cause acute reactions, coeliac disease presents unique challenges due to its chronic nature and cumulative health impacts. Sustained gluten ingestion in affected individuals leads to small intestinal mucosal damage and increases the risk of various adverse health outcomes, including nutrient malabsorption, osteoporosis, and other systemic complications.
Currently, a strict and lifelong gluten-free diet represents the only available treatment for coeliac disease. The challenge lies in the ubiquitous presence of gluten in the food supply through undeclared ingredients, cross-contact during manufacturing, and contamination all along the food supply-chain. Access to affordable, available, and safe food options remains a critical concern for individuals managing this condition.
The expert consultation: a global scientific effort
The consultation, held from 3-7 November 2025 at FAO headquarters in Rome, brought together 14 international experts representing diverse scientific disciplines and geographical regions. Under the chairpersonship of Melanie Downs from the University of Nebraska-Lincoln and with Jason Tye-Din from the Walter and Eliza Hall Institute serving as Rapporteur, the panel included specialists from Spain, China, Italy, the Netherlands, Canada, Norway, Germany, Thailand, the United Kingdom, Australia, and the United States.
This meeting responded to a specific request from the Codex Committee on Food Labelling (CCFL) for scientific advice on reference doses and concentrations for gluten and cereals containing gluten. The consultation built upon a comprehensive series of FAO/WHO expert meetings initiated in 2020, which have systematically addressed various aspects of food allergen risk assessment (FAO/WHO, 2025).
The critical recommendation: 4 mg gluten Reference Dose
The expert panel’s central recommendation establishes a reference dose (RfD) of 4 mg gluten as the threshold for risk assessment of unintended gluten presence in food products. This RfD serves as the basis for deciding whether precautionary allergen labelling (PAL) for cereals containing gluten should be applied to food products.
Scientific rationale behind the 4 mg threshold
The establishment of this RfD required a fundamentally different approach compared to IgE-mediated food allergies. While acute allergic reactions occur from single exposures, coeliac disease involves chronic, cumulative exposure risks. The expert panel therefore employed methodology similar to toxicological risk assessment for chronic exposure, ensuring that cumulative daily gluten intake does not exceed 10 mg per day.
The 10 mg per day threshold has its origins in the 2008 Codex Alimentarius Commission standard establishing that gluten-free foods should contain levels of gluten no higher than 20 mg/kg. With a daily intake of 500 g of food at this concentration, total gluten exposure would not exceed 10 mg per day. This standard was informed by a double-blind randomised controlled trial demonstrating that 50 mg of gluten daily for three months caused mucosal damage in most participants, while effects at 10 mg were not statistically significant.
Advanced modelling for chronic exposure assessment
The expert panel conducted sophisticated modelling to evaluate potential gluten RfDs ranging from 1 to 10 mg. This modelling was specifically designed to reflect chronic or cumulative daily exposure patterns rather than single-exposure scenarios. The model investigated how various RfD values would impact potential chronic daily gluten intake, incorporating multiple critical parameters:
- varying frequencies of unintended gluten presence in foods;
- population consumption amounts per day from different countries;
- multiple food product categories consumed throughout the day;
- various concentrations of unintended gluten presence;
- maximum allowed concentrations not requiring PAL within a risk-based system.
The modelling approach was deliberately conservative and attuned to real-world coeliac disease risk scenarios. Parameters were informed by peer-reviewed publications and other authoritative sources to ensure accurate representation of actual consumer exposure patterns. Importantly, the analysis included products with gluten concentrations greater than 20 mg/kg per eating occasion without risk communication regarding cereals containing gluten. Even under these conditions, the modelling did not indicate realistic exposures exceeding 10 mg per day.
With realistic parameters, gluten RfDs between 5 and 10 mg did not result in median daily gluten exposures exceeding 10 mg. The analyses demonstrated that maximum limits even with acute RfDs above 5 mg gluten could protect individuals with coeliac disease from chronic exposures exceeding 10 mg per day. To avoid establishing different RfDs for the same foods and to provide an additional safety margin, the experts agreed on the 4 mg gluten RfD recommendation.
Replacing the previous wheat protein standard
An important secondary recommendation updates previous guidance on wheat allergen labelling. The experts recommend that the previously established RfD of 5 mg total protein for wheat should be replaced with the new 4 mg gluten standard for PAL guidance. This change harmonises the approach to both coeliac disease and IgE-mediated wheat allergy, providing clearer and more consistent protection for consumers avoiding gluten and wheat.
Implications for food labelling and consumer safety
The adoption of a 4 mg gluten RfD within a risk-based PAL framework offers significant potential to enhance food safety and consumer confidence, while also strengthening legal certainty for food business operators and competent control authorities
Enhanced safety and label clarity
The new standard will significantly enhance safety and labelling clarity for consumers with coeliac disease and IgE-mediated wheat allergy. By establishing a scientifically validated threshold, food manufacturers will have clear guidance on when precautionary labelling is necessary. This evidence-based approach will reduce confusion and help consumers make informed choices about food safety.
One persistent problem addressed by these recommendations is the confusing use of both gluten-free claims and precautionary allergen labelling statements on the same product. The new framework clarifies when each type of labelling is appropriate, reducing consumer confusion and potential health risks.
Reducing unnecessary precautionary labelling
The establishment of a clear reference dose threshold should reduce unnecessary precautionary labelling. Currently, some manufacturers apply ‘may contain’ statements broadly due to uncertainty about safe thresholds. With clear scientific guidance, companies can conduct risk assessments and apply PAL only when the RfD may genuinely be exceeded. This more targeted approach benefits consumers by providing more meaningful information while maintaining safety.
Analytical and implementation considerations
The expert panel recognised several practical challenges in implementing the new reference dose standard.
Analytical method requirements
Analytical methods for gluten quantification, including those endorsed by Codex Alimentarius Commission, must be fit for purpose and validated to reliably measure the 4 mg gluten RfD. Current analytical methods face several limitations:
- Source discrimination. Existing methods cannot distinguish between gluten sources (wheat, rye, or barley), which limits the precision of risk assessment;
- Method performance criteria. The consultation identified the need for development of robust method performance criteria and more extensive provision of accessible reference materials for gluten;
- Matrix effects. Better understanding is needed of assay performance in different food matrices to ensure reliable results across diverse product types;
- Assay transparency. Greater transparency over assay-specific reagents, particularly antibodies used in enzyme-linked immunosorbent assays (ELISA), is essential as these are critical to assay performance;
- Measurement uncertainty. The inherent measurement uncertainty in current methods requires careful consideration when interpreting results near the analytical limit of quantification.
Risk communication complexities
The expert panel addressed several specific scenarios that could create consumer confusion:
- mixed gluten sources. When gluten-containing cereals are present in the ingredient list (for example, barley), and the food also contains cross-contact above the RfD from other gluten-containing cereals (such as wheat), careful labelling is essential. Competent authorities must consider how the specified cereal name and optional term ‘gluten’ appear in ingredient lists, separate statements, and PAL statements, as ‘failure to do so could lead to confusion for consumers’;
- wheat allergy communication. When PAL statements result from wheat cross-contact, the specific name ‘wheat’ should be stated explicitly to inform individuals with IgE-mediated wheat allergy, who have different threshold sensitivities than those with coeliac disease;
- large portion paradox. The experts noted a potential labelling paradox for certain products with large portion sizes (>200 grams). Such products could theoretically meet criteria for both a gluten-free claim (≤20 mg/kg) and require PAL for exceeding the 4 mg gluten RfD in a typical serving. This situation could cause confusion and potentially pose health risks to those with IgE-mediated wheat allergy who might assume safety based on a gluten-free label. The experts recommend that steps be taken to prevent these scenarios from occurring.
Food safety management systems and industry responsibility
The consultation emphasised that gluten and cereals containing gluten should be controlled through appropriate food safety management systems, consistent with approaches for food allergens described in previous FAO/WHO expert consultations. The unintended presence of gluten in foods can occur through various pathways:
- cross-contact from the supply chain, including agricultural co-mingling;
- cross-contact during the manufacturing process;
- contamination during food preparation and service.
Food business operators should implement controls to identify and manage the unintended presence of gluten and cereals containing gluten. The manner in which the 4 mg gluten RfD is implemented should align with the same risk assessment principles described in previous FAO/WHO reports on food allergens.
The RfD serves multiple purposes beyond labelling decisions. It can be applied for risk assessment and management decisions, including product recalls, compliance verification, and process improvements. When expected exposure is expressed in units of total protein from the source, conversion to mg gluten would be required for comparison to the gluten RfD.
Global context and previous FAO/WHO work
This consultation represents the culmination of a comprehensive series of expert meetings on food allergen risk assessment. Since 2020, FAO and WHO have published several reports in their Food Safety and Quality Series addressing various aspects of food allergen management:
- Part 1 (2022). Review and validation of Codex Alimentarius priority allergen list through risk assessment;
- Part 2 (2022). Review and establish threshold levels in foods for priority allergens;
- Part 3 (2023). Review and establish precautionary labelling in foods of priority allergens;
- Part 4 (2023). Review and establish exemptions for food allergens;
- Part 5 (2023). Review and establish threshold levels for specific tree nuts, soy, celery, lupin, mustard, buckwheat, and oats
The current consultation on gluten reference doses builds upon this foundation, providing scientific advice that will inform Codex Alimentarius standards evolution and support WHO, FAO member states in protecting consumers with gluten-related disorders.
Implementation timeline and next steps
The summary report issued in November 2025 facilitates deliberations by the Codex Committee on Food Labelling (CCFL) and Codex Committee on Food Hygiene (CCFH). The full report of the meeting will be published as part of the Food Safety and Quality Series, providing comprehensive technical details to support implementation.
Member states and food regulatory authorities worldwide will need to consider how to incorporate these recommendations into national regulations and food safety standards. This process typically involves consultation with stakeholders including food industry representatives, consumer organisations, healthcare professionals, and coeliac disease patient advocacy groups.
Food business operators will need to review and potentially update their allergen management programmes, including risk assessment procedures, analytical testing protocols, and labelling practices. Industry associations and standard-setting organisations such as the Global Food Safety Initiative (GFSI) may need to update their requirements to reflect the new reference dose framework.
Dario Dongo
Photo by Taís Alves
References
- FAO and WHO. (2022). Risk Assessment of Food Allergens. Part 1 – Review and validation of Codex Alimentarius priority allergen list through risk assessment. Meeting Report. Food Safety and Quality Series No. 14. Rome. https://doi.org/10.4060/cb9070en
- FAO and WHO. (2022). Risk assessment of food allergens – Part 2: Review and establish threshold levels in foods for the priority allergens. Meeting Report. Food Safety and Quality Series No. 15. Rome. https://doi.org/10.4060/cc2946en
- FAO & WHO. (2023). Risk assessment of food allergens – Part 3: Review and establish precautionary labelling in foods of the priority allergens, Meeting report. Food Safety and Quality Series No. 16. Rome. https://doi.org/10.4060/cc6081en
- FAO & WHO. (2023). Risk Assessment of Food Allergens – Part 5: Review and establish threshold levels for specific tree nuts (Brazil nut, macadamia nut or Queensland nut, pine nut), soy, celery, lupin, mustard, buckwheat and oats. Meeting report. Food Safety and Quality Series, No. 23. Rome. https://doi.org/10.4060/cc8387en
- FAO & WHO. (2025). Summary report of the Ad hoc Joint FAO/WHO Expert Consultation on Risk Assessment of Food Allergens – reference dose(s) for cereals containing gluten or gluten. Rome, Italy. FAO HQ, Rome, Italy: 3 – 7 November 2025 https://openknowledge.fao.org/items/0a455421-491b-4c44-a786-83c51452bdef
- FAO & WHO (2025). Summary report of the Ad hoc Joint FAO/WHO Expert Consultation on Risk Assessment of Food Allergens – guidance for risk assessment. FAO HQ, Rome, Italy: 16 – 20 June 2025. https://openknowledge.fao.org/items/23460c68-3c15-4fc2-8d0a-d1af6761c619
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
